The ability to predict the solubility of gases in room-temperature ionic liquids, RTILs, would be very useful in determining the most efficient RTIL to use in an industrial process. This work uses data from CO2 and C2H4 solubility measurements to show that regular solution theory can be used to model gas solubilities in RTILs at low pressures. This work further discusses how changes in pressure and temperature affect the solubility of gases in RTILs.